U.S. patent number 7,967,780 [Application Number 11/846,888] was granted by the patent office on 2011-06-28 for gastro-esophageal reflux control system and pump.
This patent grant is currently assigned to Kimberly-Clark Worldwide, Inc.. Invention is credited to Fred G. Goebel.
United States Patent |
7,967,780 |
Goebel |
June 28, 2011 |
Gastro-esophageal reflux control system and pump
Abstract
An enteral feeding unit that reduces the occurrence of
gastro-esophogeal-pharynegal reflux during feeding includes an
automatable feeding pump with a feedback sensor for sensing a
relative pressure in a patient's stomach and esophagus, and a
regulator system for controlling and monitoring feeding rate to the
patient as a function of the relative gastro-esophageal pressure.
The system includes a stomach probe that provides a fluid-tight
closure of the esophagus. The stomach probe includes a
tampon-bladder for watertight closure of the esophagus, in which
the tampon-bladder is formed of flexible and/or elastic material.
At least an inner cavity of the bladder is provided for the
reception of a fluid medium. A prescribed pressure for the medium
in the tampon-bladder (53) is maintained by an inner lumen forming
the stomach probe, from which an outer hose-like lumen (62)
extending to the tampon-bladder (53) is so arranged that between
the outer lumen (62) and the inner lumen (61) a channel is formed
connected to the inner cavity of the tampon-bladder (53) arranged
on the outer lumen (62) by a number of openings (57). The inner
cavity (58) of the tampon-bladder (53) is connected via a canal
formed between the inner and outer lumina (62) with a suitably
graded reservoir or equalizing vessel for the liquid medium
situated above the tampon-bladder and outside the patient.
Inventors: |
Goebel; Fred G. (Wilhemsfeld,
DE) |
Assignee: |
Kimberly-Clark Worldwide, Inc.
(Neenah, WI)
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Family
ID: |
40386740 |
Appl.
No.: |
11/846,888 |
Filed: |
August 29, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090062725 A1 |
Mar 5, 2009 |
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Current U.S.
Class: |
604/100.01;
604/101.02; 604/97.01; 604/96.01 |
Current CPC
Class: |
A61J
15/0073 (20130101); A61B 5/412 (20130101); A61J
15/0003 (20130101); A61J 15/0076 (20150501); A61B
5/037 (20130101); A61B 5/4211 (20130101); A61J
15/0049 (20130101); A61J 15/0084 (20150501) |
Current International
Class: |
A61M
29/00 (20060101) |
Field of
Search: |
;604/28,31,96.01,100.01,101.05,101.01,103.03,103.06-103.08,131 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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20 2006 002 832 |
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Jul 2007 |
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DE |
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Other References
M Orozco-Levi, M. Felez; E. Martinez-Miralles; J.F. Solsona; M.L.
Blanco; J.M. Broquetas; A. Torres, Gastro-Oesophageal Reflux in
Mechanically Ventilated Patients: Effects of an Oesophageal
Balloon, ERS Journals Ltd 2003, European Respiratory Journal, pp.
348 to 353. cited by other .
Written Opinion of the International Searching Authority /
International Search Report, dated Jan. 12, 2009. cited by
other.
|
Primary Examiner: Sirmons; Kevin C
Assistant Examiner: Thomas, Jr; Bradley G
Attorney, Agent or Firm: Dority & Manning, P.A.
Claims
I claim:
1. An anti-gastro-esophageal reflux device for use during enteral
feeding, the device comprising: a pressure-regulating unit; a tube
having a double lumen, a gastric balloon, and an esophageal
bladder, said gastric balloon being connected by a first conduit to
said pressure-regulating unit and configured to be disposed in the
patient's stomach to sense the gastric pressure therein, said
esophageal bladder being connected by a second conduit to said
pressure-regulating unit, said esophageal bladder having a
compressible volume and an outer surface with a plurality of pleats
that are configured to intermesh with a patient's esophagus wall
structures, and said pressure-regulating unit being configured to
maintain a pressure within said esophageal bladder at a level
greater than the gastric pressure exerted on said gastric balloon
when the anti-gastro-esophageal reflux device is in use.
2. An anti-gastro-esophageal reflux device for use during enteral
feeding, the device comprising: a tube having a double lumen; a
gastric pressure sensor configured to be disposed in the patient's
stomach to sense the gastric pressure therein and configured for
monitoring gastric pressure when enteral feeding is in process; an
esophageal bladder having a compressible volume and an outer
surface with a plurality of pleats that are configured to intermesh
with a patient's esophagus wall structures; a control device that
is connected via a first conduit to said esophageal bladder and
configured to regulate fluid pressure within said esophageal
bladder, said gastric pressure sensor being connected in
communication with said control device, said control device
including a filter algorithm configured to provide an averaged
signal from signals received from said gastric pressure sensor,
said control device being configured to add a pre-set gradient
value to said averaged signal to define a relative level of
esophageal seal pressure, and said control device being configured
to maintain said relative level of esophageal seal pressure within
said esophageal bladder when the anti-gastro-esophageal reflux
device is in use.
3. An anti-gastro-esophageal reflux device according to claim 2,
further comprising: a feeding pump configured to deliver feeding
solution at a feeding rate over a time interval, said feeding pump
being configured to sense the relative amount of pressure in a
patient's stomach as well as the relative amount of pressure in a
patient's esophagus and to adjust the feeding rate according to the
relative amount of pressure in a patient's stomach as well as the
relative amount of pressure in a patient's esophagus when the
anti-gastro-esophageal reflux device is in use.
4. An enteral-feeding device comprising: an automatable feeding
pump; a control device having a feedback sensor for sensing a
pressure gradient between the pressure in a patient's stomach and
the pressure in a patient's esophagus, said control device being
configured for controlling and monitoring the pump's feeding rate
to the patient as a function of said pressure gradient; a
pressure-regulating unit; a tube having a double lumen, a gastric
balloon, and an esophageal bladder, said gastric balloon being
connected by a first conduit to said pressure-regulating unit and
configured to be disposed in the patient's stomach to sense the
gastric pressure therein, said esophageal bladder being connected
by a second conduit to said pressure-regulating unit, said
esophageal bladder having a compressible volume and an outer
surface with a plurality of pleats that are configured to intermesh
with a patient's esophagus wall structures, and said
pressure-regulating unit being configured to maintain a pressure
within said esophageal bladder at a level greater than the gastric
pressure exerted on said gastric balloon when the
anti-gastro-esophageal reflux device is in use.
5. An enteral-feeding device according to claim 4, wherein said
feedback sensor includes a gastric balloon and an esophageal
bladder.
6. An enteral-feeding device according to claim 4, wherein said
control device includes a timer device configured for controlling
said feeding rate, and wherein said timer device can be adjusted
either manually or electronically as a function of said pressure
gradient and the amount of feeding solution to be fed to the
patient.
7. An enteral-feeding device according to claim 5, wherein said
control device is configured to deliver a defined volume of fluid
into said gastric balloon to fill said balloon to a volume smaller
than the gastric balloon itself in its freely inflated preshaped
state.
8. An enteral-feeding device according to claim 7, wherein said
gastric balloon is inflated up to about 75-80% of a volume in free
inflation without hull distension.
9. An enteral-feeding device according to claim 4, wherein once a
pressure in said gastric balloon reaches a stable reading of the
intra-gastric filling pressure, said control device is configured
to regulate said esophageal seal pressure at a predetermined value
that is calculated by computer software or that is defined by a
user.
10. An enteral-feeding device according to claim 4, wherein a
desired value for a range or limit for the pressure gradient
(.DELTA.P), affecting esophageal pressure parameters, is calculated
thus: the pressure in the patient's stomach+.DELTA.P value.
11. An enteral-feeding device according to claim 4, wherein said
feedback sensor is a gastric balloon and said control device is
configured to adjust the pressure in said gastric balloon to
compensate for changes in pressure and conditions in the patient's
abdominal and thoracic cavities contiguously over a course of
enteral feeding.
12. An enteral-feeding device according to claim 4, wherein said
control device is configured to permit a user to enter a desired
feeding volume to be administered over a predetermined period, such
that volume and time values can be separately defined and
programmed to achieve the desired feeding regime.
13. An enteral feeding device according to claim 4, wherein said
control device includes computer software that determines an actual
rate of feed volume delivered over a primary feeding time
interval.
14. An enteral-feeding device according to claim 4, wherein said
control device has a visual display for volume/time calculations
and is programmable by a user to enter a desired feeding time
interval and calculate a volume of feeding solution delivered
within a preset unit of time or over an entire contiguous feeding
period selected.
15. An enteral feeding device according to claim 4, wherein said
control device has a memory system that enables said control device
to apply a software-preset or user-defined feeding rate to
determine relative compliance of a patient's stomach against said
feed volume.
16. An enteral feeding device according to claim 4, wherein said
control device automatically increases a slope of a determined
graph (V/P), based on relative pressure increase over an applied
volume, to reach a desired volume (V/t.sub.total).
17. An enteral-feeding device according to claim 4, wherein once
said feedback sensor detects a maximum gastric under a given
parameter setting, said control device will pause said feeding pump
intra-gastric pressure has sufficiently decreased to within
predetermined feeding levels before controlling said pump to resume
feeding the patient.
18. An enteral-feeding device according to claim 4, wherein said
control device is configured to calculate and determine
continuously, hourly and expected feeding volumes over a selected
time interval.
Description
FIELD OF INVENTION
The present invention relates to a system for preventing
gastro-esophageal reflux by regulating or counterbalancing stomach
pressure generated during and in between episodes of
gastric-enteral feeding of a patient.
BACKGROUND
Spontaneous release of gastric pressure is often associated with
reflux, which is the transport of stomach contents to the pharynx.
Gastro-esophageal "reflux fluid" as used herein includes any gas,
any liquid, any partially solid and liquid substance or any
material that can be expelled from the stomach into the patient's
pharynx. Fluids that commonly accumulate in the stomach of a
tube-fed patient include the tube-feeding formula, swallowed saliva
(more than about 0.8 L/day), gastric secretion (about 1.5 L/day),
and regurgitated small bowel secretion (about 2.7 to 3.7 L/day)
into the stomach. Gastro-esophageal reflux (GER) often appears as
an intermittent more or less massive, bolus-like regurgitation of
stomach contents, but also can manifest as a continuous, silent
ascension and descension of liquid and solid material between the
gastrointestinal tract and the pharyngeal tract. GER alongside of
gastric feeding and decompression tubes in intubated patients, both
ventilated and spontaneously breathing, is a common problem in ICU
therapy, being associated with a high infection relevance.
Especially under so called intra-gastric or intra-duodenal feeding,
the incidence of reflux of stomach contents into the pharynx of the
patient is increased. Gastric, duodenal or enteral feeding is a
form of hyper-alimentation and metabolic support in which nutrient
formulas or medicaments are delivered directly to the
gastrointestinal tract, either the stomach or the duodenum. In the
majority of cases, nutrient administration is accomplished through
use of a tube based device or system, delivering the nutrient
through the patient's pharynx and esophagus directly into the
stomach, the duodenum or small intestinum (jejunum), often referred
to as so-called enteral feeding. Certain enteral feeding devices
include pumps that deliver feeding fluid to the patient. Other
enteral feeding devices rely upon gravity to move the feeding fluid
from a container (suspended above patient level) to the
patient.
Enteral tubes for providing food and medication to a patient have
been used in medical settings for many years. Examples of enteral
feeding devices are described in U.S. Pat. Nos. 4,666,433;
4,701,163; 4,798,592; and 4,685,901, which are hereby incorporated
herein in their entireties for all purposes by this reference. In
critical care therapy, gastric (enteral) feeding is usually
performed via so called naso-gastric decompression catheters
(NG-tubes), which are primarily used to release pressure building
up in the stomach of a patient. Excessive gastric pressure may
result from the accumulation of liquid intestinal secretions,
feeding solution applied into the stomach or duodenum, abdominal
motility, body movement or positioning of the patient, or through
normal formation of gas. For decompression of gastric pressure and
drainage of gastric contents, such patients may be intubated with
so called naso-gastric or oro-gastric tubes or probes. An example
of one such stomach probe is described in German Utility Model
Application No. 202006002832.3. Another is described in U.S. Pat.
No. 6,551,272 B2, which is hereby incorporated herein in its
entirety for all purposes by this reference.
Because solids and/or higher viscosity liquid secretions frequently
obstruct the drainage lumen of a stomach probe, in many cases
stomach probes insufficiently decompress the stomach. The
insufficient decompression of the stomach permits reflux of fluids
through the esophageal lumen alongside the NG tube. Further,
instead of preventing GER, the literature describes the
trans-esophageal passage of the rigid decompression tube shaft as
itself impairing the seal efficacy of the esophagus and its
sphincters by partially opening the sphincters and thus
facilitating the ascension of secretions from the stomach into the
pharynx alongside the tube shaft. Studies have shown that while GER
occurs in about 15% of supine positioned patients without NG tubes,
the prevalence of GER in supine positioned patients with NG tubes
may increase to about 80% of cases.
Moreover, GER occurs in critically ill patients even in the absence
of nasogastric (NG) tubes and enteral delivery of feeding
solutions. Up to 30% of patients who are kept in the supine
position are estimated to have GER.
The free communication of secretions between pharynx and stomach
often results in a state of continuous ascension and decension of
high volumes of colonized fluids, which may be on the order of
several hundred milliliters per day or even on the order of liters
per day. Typically, after about 4 to 6 days of mechanical
ventilation, a mixed bacterial flora becomes established and
populates the upper GI-tract as well as the entity of the
pharyngeal, i.e., cranio-facial cavities. Such colonized material
may pool in predisposed spaces such as the maxillary or sphenoidal
sinuses, representing a most relevant source for bacteria inducing
so called ventilator-associated pneumonia (VAP) as well as an
origin for the septic spread of bacterial pathogens.
The free communication between the pharyngeal and gastro-intestinal
compartment also impairs gastric delivery of enteral feeding
solutions, which frequently becomes a problem in administering
sufficient calories in the natural way via the upper GI-tract, and
may require expensive and complication associated par-enteral
feeding. In many cases, one can observe that feeding solution runs
out of the patient's oral and nasal openings, implying that the
reflux volume has been high and that all cranio-facial surfaces
have been covered with a layer of bacteria feeding nutrients,
supporting a major reservoir of pathogenic bacteria, especially in
the etiology of VAP.
Preventive strategies against reflux of gastro-esophageal contents
were essentially medicinal/antibiotic based, as for example
so-called selective digestive decontamination (SDD) of the pharynx
and the stomach by application of topical, non-resorbable
antibiotics. Additionally, oral care procedures are being performed
on most ICU wards, whereby the oro-pharyngeal cavity is cleaned by
a swab or a brush, applying a small volume of water or cleaning
solution into the oro-pharynx. Further, medication has been
administered to long term ventilated patients, preventing bacterial
colonization of the stomach by keeping the stomach pH within an
acidic, antiseptic range.
Perhaps the most frequently practiced and probably most efficient
preventive measure against reflux of gastro-esophageal contents has
been to elevate the patient's upper body into a semi-recumbent
position, thereby reducing the ascension of colonized gastric
material into the pharynx. At least two studies have shown a
reduction of GER when critically ill patients are kept in the
semi-recumbent position. Thus, patients undergoing mechanical
ventilation are usually put in a supine or a semi-recumbent body
position.
When gastrointestinal motility is normal, secretions and ingested
fluids are propelled forward by the upper gastro-intestinal tract
with little difficulty. Significant gastrointestinal dysmotility,
ranging from moderate delay in gastric emptying to marked gastric
paresis, has been described in patients with a variety of clinical
conditions such as burns, sepsis, trauma, surgery, and shock. GER
frequently can be observed during tracheal intubation and
mechanical ventilation, where sphincter function and gastric
motility may be impaired as a side effect of the analog-sedating
medication applied, and an extended period of demobilization of the
patient in supine position. In order to prevent reflux under
gastric feeding, respectively to support gastric and duodenal
motility and emptying, ICU clinicians administer special drugs like
e.g. metoclopramid.
When the combination of feeding solution blended with
gastro-intestinal fluid can freely communicate between the upper GI
tract and the entity comprised of all the cranio-facial spaces
connected to the patient's pharynx, the patient can suffer severe
consequences in several regards: First, feeding solution is lost,
and necessary calories cannot be administered successfully,
resulting in the need for costly prolonged par-enteral patient
feeding. Second, the mucosal surfaces of the cranio-facial cavities
are getting covered intermittently with nutrients contained in the
feeding solution, providing ideal growth conditions for bacteria,
increasing the risk of colonization with bacteria relevant for the
development ventilator associated pneumonia (VAP). Pharyngeal
secretions, descending via the tracheal tube cuff to the distal
airways are known to be a major cause of pulmonary infections in
the intubated and ventilated patient. Third, feeding solution,
which is pooling in the remote cranio-facial cavities as the
naso-pharynx and the para-nasal sinuses, cannot be removed by state
of the art care techniques, may turn into a purulent state and
become a permanent source for VAP pathogens or bacteria causing
septic complications, by so called translocation of the bacteria
through the inflamed mucosa from the purulent pool into the blood
stream.
The measurement of esophageal and gastric pressures with
balloon-tipped catheters has been employed with great success over
the past half century to delineate the physiology of the
respiratory system. The determination of so called
trans-diaphragmatic pressure, which is usually detected by sensing
the pressure gradient between a balloon element disposed in the
esophagus and a balloon element disposed in the stomach or
intestine, has led to the development of according measuring probes
and pressure sensing hardware, whereby the balloons are small in
dimension and incapable of effecting an esophageal seal function.
The related hardware is set for pressure detection exclusively and
cannot actively regulate a seal pressure gradient.
In recent years there have been clinical attempts to effect an
esophageal balloon seal against gastric material ascending from the
stomach into the pharynx, using probe material designed for
esophageal bleeding intervention (Sengstaken Blakemore tubes).
Orozco et al. (details) were able to show a significant reduction
of gastro-esophageal reflux. However, the structures of the
esophageal wall react extremely sensitively to persistent pressure
or organ wall distension. Thus, such conventional blocking
techniques, in which the hull of a sealing bladder structure is
placed under tension, are not, or only with limitations, desirable
in the case of the esophagus. Due to the potential esophageal
trauma risk, the application period of the stationary pressured
balloon was limited to 8 hours.
A stomach probe such as described in German Utility Model
Application No. 202006002832.3 has an esophageal bladder and
enteral feeding tube that are integrated such that the feeding tube
sits at or near the center of the bladder when used in a patient.
The feeding tube has a thin-walled bladder associated with the
feeding lumen. Around the feeding lumen is either one or a
plurality of ferrules that are used to conduct air or other gas
along the length of the bladder. A stomach probe of this type has a
lumen that is located on the delivery cannula in the region of the
inflatable bladder, which arrangement guarantees a rapid
equalization of volume between sections or partial volumes of the
inflatable bladder. The lumen is arranged so that a channel is
formed between the lumen and the delivery cannula, which is
connected to the interior of the inflatable bladder via a number of
openings, and which is arranged on the lumen. The interior of the
inflatable bladder is connected to means for producing pressure in
the inflatable bladder via the channel formed between the delivery
cannula and the lumen. The lumen is thereby kept open by stent-like
devices or spacers between an outer and an inner wall of the probe
or the delivery cannula of the stomach probe. However, a stomach
probe of this type is therefore much more complicated to produce
than conventional stomach probes without a lumen, for example.
SUMMARY OF THE INVENTION
According to the present disclosure, a pressure gradient based
esophageal seal is provided that is optionally self-adjusting to
continuously changing seal pressure requirements as well as to
long-term organ compatible and atraumatic intra-esophageal bladder
placement.
The present disclosure rectifies the disadvantages associated with
conventional gastric or duodenal decompression and feeding
catheters. The present disclosure includes a decompression or
feeding probe that enables a clinician to close off or seal a
patient's esophagus over extended periods well in excess of eight
consecutive hours, without causing patient irritation and without
causing deleterious effects on the esophageal structures. By
interrupting the free communication between the gastro-intestinal
tract and the upper respiratory tract, gastro esophageal reflux of
stomach contents into the pharynx can be reduced. Thus, the
efficacy of gastro-duodenal application of feeding solution can be
improved, and the amount of bacterial colonization of the pharynx
and the adjunct cranio-facial cavities can be lowered.
In one aspect of the disclosure, a pressure sensor element placed
inside the stomach continuously senses intra-gastric pressure and
reports to a control device/unit that accordingly regulates the
filling pressure of an esophageal placed organ sealing bladder. In
one mode, the control device/unit regulates the filling pressure of
the esophageal placed organ sealing bladder according to a pressure
that is manually set at a predetermined constant pressure. This is
the manually set and operated stationary mode. In another mode, the
control device/unit regulates the filling pressure of the
esophageal placed organ sealing bladder according to a pressure
that is constantly changing and that is the pressure measured by a
second pressure sensor placed in the esophagus. This is the
self-regulated or dynamical mode. Each mode enables the setting of
a user determined continuous seal pressure gradient by which the
pressure in the esophageal seal bladder exceeds the intra-gastric
pressure, thereby effecting a pressure gradient that serves a
reflux-preventive esophageal seal function against
gastro-intestinal contents ascending from the stomach past the
esophageal seal bladder.
The control device/unit can be connected or integrated into a
feeding pump that delivers the feeding solution to the patient.
Such integration enables the above described regulation of a
pressure gradient-based esophageal seal function, preventing
especially the ascension and loss of pharyngeal feeding fluid into
the pharynx, as well as creating a pressure gradient between the
stomach and the duodenum, facilitating the spontaneous emptying of
the stomach and intestinal directed flow of feeding solution. The
combination of seal pressure control device and feeding pump
provides the ideal tool for the user not only for improving the
efficacy of enteral feeding, but also, reducing the amount of GER
in the periods intermittent of gastric feeding, thus having a
preventive effect on the development of VAP. Further, the feeding
pump unit can integrate special control algorithms that improve the
intestinally directed uptake of feeding solution and reduce
potential traumatic effects of a permanently exposed seal force on
the pressure sensitive esophageal structures.
Additionally, a particular oro/naso-gastric/duodenal catheter
design for combined use with the above described control device or
control device/pump combination is described. The catheter can be
provided with a lumen, which is located between the delivery
cannula and an inflatable tampooning esophageal bladder and which
is connected to the interior of the inflatable bladder. The
catheter can be produced by a relatively simple technique, and at
the same time guarantees adequate volume equalization between the
partial volumes of the inflatable bladder. The catheter desirably
includes: a tube having at least a double lumen, a gastric pressure
sensor element and an esophageal tampon bladder, whereby the
gastric pressure sensor and the tampooning esophageal bladder are
connected to a pressure sensing and regulating control-device. The
esophageal bladder can be pre-shaped to a residually dimensioned
preformed diameter that includes a plurality of pleats that can
intermesh with the mucosal folding of a patient's esophagus. In
this way, in order to effect a sufficient seal of an expanding
esophageal lumen, the pleated wall of the tampon bladder need not
be stretched by increasing the internal pressure, but rather merely
unfolds at the same pressure and can therefore resize itself
sufficiently to cover the physiologic axially directed folding of
the esophageal mucosa at the lowest possible filling pressure. This
unfolding mechanism essentially effects a tamponade of the
remaining open lumen in the esophagus, instead of creating a
pressure intensive organ blockage, as effected by conventional
compliant, expandable bladder materials. Further, the tampon
carrying segment of the catheter shaft may be equipped with a
special shaft profile, enabling the esophageal placed tampon to
withstand peristaltic contractions by performing an intra-tampon
volume shift of the applied filling medium from the portion distal
of the peristaltic contraction into the portion proximal and
already released of the peristaltic contraction.
In another aspect, the present invention relates to a method or
process for effectively reducing gastric reflux into a patient's
esophagus. The method involves: providing an enteral feeding tube
having at least a double lumen, an esophageal seal bladder and a
gastric pressure sensor element (e.g., gastric balloon); inserting
said enteral feeding tube into said patient's upper alimentary
canal, to position said gastric balloon in said patient's stomach
and said esophageal bladder in said patient's esophagus; receiving
from the gastric pressure sensor element an intra-gastric pressure
signal that can be averaged using a filter algorithm; setting of a
user determined gradient value that is continuously added to the
sensed actual gastric pressure, thereby defining a relative level
of esophageal pressure that should be applied to seal the esophagus
from gastro-pharyngeal reflux, respectively enabling the built-up
of a pressure gradient directed from the stomach towards the
duodenum, facilitating the emptying of the stomach contents into
the distal digestive tract.
Other features and advantages of the present system and individual
devices or components will become evident from the following
detailed description. It is understood that both the foregoing
general description and the following detailed description and
examples are merely representative of the invention, and are
intended to provide an overview for understanding the invention as
claimed.
BRIEF DESCRIPTIONS OF DRAWINGS
FIG. 1 is a general schematic representation of an embodiment of
the present invention as inserted in a silhouette outline of a
patient's head, torso and upper abdomen with a diagram of a pump
system according to an embodiment of the present invention.
FIG. 2 is partial cut-away illustration of an embodiment of the
esophageal bladder device and feeding tube according to an
embodiment of the present invention.
FIG. 3 is a cross-sectional view of the device shown in FIG. 2,
along line II-II, as it may sit in the esophagus.
FIG. 4 shows a perspective view of a shaped body shown in FIGS. 2
and 3, according to a first embodiment.
FIG. 5 shows a perspective view of a delivery cannula.
FIG. 6 shows a perspective view of a disclosed shaped body
according to a second embodiment.
FIG. 7 shows a perspective view of a disclosed shaped body
according to a third embodiment.
FIG. 8 shows a schematic view of an alternative design for the
ferrule.
FIGS. 9 and 10 show variations of the design of FIG. 8.
DETAILED DESCRIPTIONS OF ILLUSTRATIVE EMBODIMENTS OF THE
INVENTION
The present invention describes a device and method, which effects
a static or dynamical, low irritating, long-term organ compatible
and stationary seal function within the esophagus, intending to
interrupt the above described free communication of secretions and
gastric material between the upper respiratory tract and the
gastro-intestinal tract.
Referring to FIG. 1, which schematically illustrates a
cross-section of part of a patient's torso, the patient's chest
cavity wall 11, lungs 12, diaphragm 13, intra-thoracic space 14,
esophagus 15, and stomach 18 are depicted. Also depicted in FIG. 1
is a presently preferred embodiment of an anti-gastro-esophageal
reflux device for use during enteral feeding as it may operate in
situ in a patient's thorax in combination with a feeding pump
function/unit. As schematically illustrated in FIG. 1, an
embodiment of a seal system includes a combination of a gastric
tube 54 inserted through the nasal or oral cavity, passing through
the esophagus 15, and terminating in the stomach 18. The
oro/naso-gastric tube 54 has a pressure sensing balloon 21, which
alternatively can be provided by an electronic pressure sensing
element 21, situated near the end of the tube's tip that is
situated in the stomach 18. This gastric balloon/sensor 21 is
connected to a respective filling/communication line 23. Proximal
of the gastric sensor balloon 21 is situated an esophageal sealing
bladder 53 with a filling line 22 along or integrated in the shaft
of the naso-gastric tube 54.
As schematically shown in FIG. 1, in accordance with a presently
preferred embodiment of the invention, a decompression/feeding tube
54 can be specially designed for combined use with a sensing and
regulating device 20, which is configured to receive signals from
one or more pressure sensors and is configured to regulate the seal
force in the esophagus 15 according to the sensed pressure(s). As
schematically shown in FIG. 1, the control device 20 can be
integrated with a feeding pump 24, such as a roller pump 24, or
similar mechanism used in gastric feeding pumps for delivering
feeding solution from a reservoir 38 via a tube segment 19 to the
patient's stomach 18. The combination provides the benefit of a
regulated reflux-preventive esophageal seal 53, especially suited
for the requirements of enteral feeding of a critically ill
patient.
The control device 20, which desirably is configured to receive and
process signals from pressure sensor 21 and to regulate the seal
force exerted by the bladder 53 on the wall 16 of the esophagus 15,
desirably can include mechanical pump/pumps, pressure transducers,
analog-digital-converters, and a logical/control unit such as a
programmable logic controller and/or a programmable
microprocessor.
The control device 20 desirably can be configured to continuously
monitor and optionally display the actual intra-gastric pressure
sensed by sensor 21 and to regulate the inflation pressure of the
esophageal seal bladder 53 so as to ensure a user determined
pressure gradient (.DELTA.P) between the sealing esophageal bladder
53 and the pressure inside the stomach 18 to seal against. As
schematically shown in FIG. 1, the control device 20 or regulator
mechanism can be provided with a display 25 for feedback from
sensors and other parameters. The display 25 can be configured to
provide a visual display of the user determined pressure gradient
between esophageal and gastric pressure (.DELTA.P), the actual and
desired volume/unit time (V/h) of nutrient to be fed to the
patient, the esophageal pressure (P.sub.esophagus) sensed by the
seal bladder 53, and the gastric pressure (P.sub.gastric) sensed by
the gastric sensor 21.
The control device 20 or regulator mechanism can be provided with
manual controls for regulating the rate at which feeding solution
is supplied to the patient and other parameters. As schematically
shown in FIG. 1, the control device 20 can be provided with a
manual input mechanism 26 option that enables the user to set the
magnitude of the desired pressure gradient .DELTA.P. As
schematically shown in FIG. 1, the control device 20 can be
provided with a manual input mechanism 27 for controlling the
volume of nutrient to be fed to the patient, a manual input
mechanism 28 for controlling the delivery time during which
nutrient is to be fed to the patient, and a manual input mechanism
39 for controlling the connection of the system to a feeding
container 38 that contains the feeding solution.
By continuously adding the user determined seal pressure gradient
(.DELTA.P) to the actual intra-gastric pressure detected by sensor
21, the force exerted by the esophageal seal 53 against the
esophageal tissue 16 can be continuously reduced to the required
minimum and thus reduce accordingly the likelihood of pressure
induced trauma that otherwise might be caused by continuous,
inappropriately high seal pressures. If the level of intra-gastric
pressure is relatively low, then the esophageal seal force and
trans-murally effected force is commensurately relatively low. If
the level of gastric pressure increases, then the esophageal seal
pressure only is increased by a gradient (.DELTA.P), which can be
determined by the user as being sufficient for reflux prevention.
Stationary, high seal pressure gradients that exceed the actually
required seal force thus can be prevented.
Alternative to a continuous adjustment of esophageal seal pressure
to actual intra-gastric pressure, the addition of the user
determined seal pressure gradient (.DELTA.P) to the actual
intra-gastric pressure can be performed intermittently within time
intervals that can be pre-set or fixed by the user in the control
device 20 as by a manual input mechanism 28 for controlling the
time interval for feeding nutrient to the patient or determined by
a manual mode, whereby the user determines the addition of the seal
gradient (.DELTA.P) to the gastric pressure by e.g. manually
entering the desired seal gradient .DELTA.P, which remains
effective till the manual adjustment is repeated.
Integrated into or connected to a feeding pump 24, the control
device 20 for regulating the esophageal seal force can be
configured to actively keep the seal pressure of the esophageal
bladder 53 in dynamic accordance with the actual intra-gastric
pressures reached under ongoing and post-gastric feeding, so that a
seal-sufficient pressure gradient (.DELTA.P) between
intra-esophageal pressure and the intra-gastric stomach pressure
can be continuously maintained. The control device 20 can be
configured to control the feeding pump unit 24 to further control
the relative feeding rate to a patient as a function of the gastric
pressure sensed through the gastric pressure sensor 21, thereby
preventing critical esophageal seal forces from being reached and
feeding the nutrient under optimal pressure conditions and/or
during optimal feeding periods.
Algorithmic Control
Analogous to a ventilation control technique, such as described in
U.S. Pat. No. 7,040,321 B2, which is incorporated herein in its
entirety for all purposes by this reference, the present enteral
feeding system also desirably can use an algorithmic control for
controlling the feeding pump. A possible example of such an
algorithmic control could include the following. After placement of
a gastric probe 21 and activation of the system, the control device
20 can be configured to pump a defined volume of filling fluid via
filling line 23 into the gastric balloon 21 to fill the balloon,
which is preferably smaller than the volume of the gastric balloon
21 in its freely inflated pre-shaped state. As schematically shown
in FIG. 1, the control device 20 can be configured to operate a
pump 41 connected via filling line 23 to the gastric pressure
sensing balloon 21 to fill the balloon 21.
By inflating the gastric sensor balloon 21 partially, it remains in
a floppy non-extended state, being able to respond to slightest
changes of intra-gastric, i.e., intra-abdominal pressure. Once the
pressure within the balloon 21 reaches a stable reading of the
intra-gastric pressure (i.e., a mean pressure level derived through
an averaging process), the control device 20 can be configured to
operate a pump 40 connected via filling line 22 to apply the
esophageal seal pressure to the esophageal seal tamponade 53 via
filling line 22. The esophageal seal pressure desirably can be
regulated by the control device 20 on the basis of a predetermined
.DELTA.P value that can be preset in the software of the control
device 20 and can be manually adjusted by a user via the input
mechanism 26. The esophageal seal pressure calculates as the
gastric pressure (measured by the gastric sensor 21) plus the
.DELTA.P value.
As schematically shown in FIG. 1, the filling fluid for the sensing
balloon 21 and the esophageal seal tamponade 53 can be supplied
from a fluid reservoir 35, which can hold a liquid or a gas, at
room conditions or under pressure as the case may be.
Due to the particular membrane characteristics of the foil of the
sealing esophageal bladder 53, a hydrostatic pressure gradient of
about 10 cm to about 20 cm of water above the actual gastric
pressure is considered desirable to produce a reliable seal against
passive reflux of gastric contents. Typically, a hydrostatic
.DELTA.P pressure of up to about 10 cm is employed.
As schematically shown in FIG. 1, the actual esophageal seal
pressure to be maintained in the esophageal seal bladder 53 can be
constantly determined and adjusted by the control device 20 that
operates a pump 40 connected via filling line 22. The control
device 20 desirably is configured to derive this seal pressure from
the actual intra-gastric pressure detected by the gastric
balloon/electronic sensor 21 and the seal pressure gradient
.DELTA.P that has been set by the user via manual input mechanism
26. In order not to exceed a pressure level in the esophageal seal
53 that may cause tissue infarction and possibly cause ulcers, the
control software employed by the control device 20 can be
configured to contain a preset value P.sub.esophagus-max, defining
a maximum seal pressure not to be exceeded by the esophageal seal
bladder 53.
The control device 20 desirably can be configured to permit the
user to enter via input mechanism 27 a desired volume of feeding
solution to be administered over a certain time period, whereby the
duration of the delivery interval of the volume of the feeding
solution to the patient can be separately defined or entered by the
user via manual input mechanism 28 as another of a predefined set
of parameters. The control device 20 can be configured to calculate
a constant flow rate that is able to deliver the desired volume of
feeding solution over the desired delivery period. The control
device 20 desirably can be configured to operate the patient's
nutrient feeding pump according to several modes, including the
following examples.
--Operation Under Constant Flow:
This mode of operation calls for continuous adjustment of
esophageal seal pressure according to a user defaulted seal
pressure gradient, following operation of the feeding solution pump
according to a machine calculated linear feeding rate, which is
calculated to be able to deliver the desired volume of feeding
solution over a desired time interval, automatically stopping of
the feeding pump function when P.sub.esophagus-max is reached,
pausing of the feeding pump function till P.sub.esophagus has
dropped below P.sub.esophagus-max, continuation of the feeding pump
function according to the initially calculated feeding rate, till
delivery of the desired total fluid volume of the feeding solution
has been accomplished.
--Operation Under Dynamically Adjusting Flow--Delivery Volume
Oriented:
This mode of operation calls for continuous adjustment of
esophageal seal pressure to try to maintain a user-preselected
defaulted seal pressure gradient A P.sub.gastric. The control
device 20 is configured to perform a continuous or intermittent
determination of A P.sub.gastric over .DELTA.t (control software
defined time intervals, e.g., 3 minutes before and after the actual
pressure value determination), linear extrapolation of .DELTA.
P.sub.gastric over .DELTA.t, in case the slope of extrapolated
pressure curve P.sub.gastric reaches P.sub.esophagus-max within
.DELTA.t (or several .DELTA.t periods, or the total user determined
delivery period), a reduction of the feeding solution flow rate is
figured and executed by the control algorithm, which is configured
to lower the slope of the extrapolation sufficiently so as not to
exceed P.sub.esophagus-max within .DELTA.t (or several .DELTA.t
periods, or the total user determined delivery period), dynamical
extension of the feeding period till the desired total volume of
feeding solution has been delivered.
--Operation Under Dynamically Adjusting Flow--Delivery Time
Optimized:
This mode of operation calls for continuous adjustment of
esophageal seal pressure according to a user-preselected defaulted
seal pressure gradient, continuous or intermittent determination of
.DELTA. P.sub.gastric over .DELTA.t (control software defined time
intervals, e.g. 3 minutes before and after the actual pressure
value determination), linear extrapolation of slope (see above), if
extrapolated pressure curve of P.sub.gastric does not reach
P.sub.esophagus-max within .DELTA.t (or several .DELTA.t periods,
or the total user determined delivery period), successive increase
of flow rate to reach or nearly reach P.sub.esophagus-max within
.DELTA.t (or several .DELTA.t periods, or the total user determined
delivery period). Automatic stopping of the feeding pump function
is effected when P.sub.esophagus-max is reached, the feeding pump
function is paused till P.sub.esophagus has dropped below
P.sub.esophagus-max, the feeding pump function is resumed according
to the prior calculated feeding rate of the feeding solution, till
delivery of the desired total fluid volume of the feeding solution
has been accomplished.
--Operation Under Dynamically Adjusting Flow--Delivery Time
Optimized and Delivery Volume Oriented:
This mode of operation calls for operating according to the
delivery time optimized mode as described above utill
P.sub.esophagus-max is reached, then changing to the delivery
volume oriented mode as described above.
Gravity-Operated Feeding Control:
The feeding solution can be supplied using gravity instead of by a
mechanical pump. When the feeding process is gravity driven, the
process can be controlled by an electronic occlusion element (not
shown) that interrupts or gradually controls the flow and amount of
the delivered feeding solution. A dripping chamber (not shown) can
be integrated into a feeding line 19, and an optical detection
device (not shown) can be used to detect and count the number of
drops of feeding solution entering such chamber in order that the
flow and volume of feeding solution can be detected and used to
control the occlusion element. Thus, the above suggested control
algorithms can be used in a manner similar to the computer
program-assisted control described above.
ITP as a Parameter
By inflation of the esophageal bladder 53, the gastric probe 54
that can be introduced into the esophagus 15 is placed against the
surface of the wall 16 of the esophagus 15, which in its middle
portion and even better in its lower third transmits the pressure
course inside the thorax through the wall 16 of the esophagus 15
(transmurally) to the esophageal placed bladder 53 of the gastric
probe 54. The inter-transmural pressure (ITP) that is transmurally
transmitted through the wall 16 of the esophagus 15 is detected by
this bladder 53 and becomes a measured value that can be used as a
control signal indicative of the pressure inside the esophagus 15
and that can enable the user to detect and monitor chest movement
activity of the patient.
Probe Design Requirements:
The outer diameter of the delivery cannula 54 is advantageously
between about 3 mm and about 6 mm, and especially between about 4
and about 5 mm. In the interior of the delivery cannula 54, in
addition to a nutrient channel 61, through which liquid nutrients
are delivered to the patient, there is a delivery channel 62, via
which the inflatable bladder 53 can be filled with a fluid, whether
gaseous or liquid.
The performance of the device and the method, to prevent gastric
content from ascending into a patient's pharynx via the esophagus
15, further depends on the specific design and a particular
performance of the esophageal sealing bladder 53. To prevent
pressure-induced esophageal lesions, the present invention
describes a low-pressure bladder tamponade/occlusion of the
esophageal organ lumen. Next to the prevention of pressure induced
esophageal lesions, the esophageal sealing bladder 53 must be
configured to meet the requirements of permanent placement inside
the esophagus' highly dynamic structure that is constantly in
movement and changing cross-sectional mucosal folding and shape. On
account of these difficulties, the search for a simple designed
intra-esophageal bladder seal, which is atraumatic, not irritating,
withstanding peristaltic movement, and effecting a sufficient
mechanical separation of airway and digestive tract, could not
until now be satisfactorily resolved. The functional features of
the invented bladder equipped decompression probe described in the
invention meet such requirements.
Residual Bladder
The diameter of the inflatable bladder 53 in a freely unfolded
condition is between about 20 mm and about 50 mm. A diameter of
about 30 mm to about 40 mm is particularly desirable for the
diameter of the inflatable bladder 53 in a freely unfolded
condition. The tampooning bladder 53, when freely inflated to its
full pre-shaped dimension, has a larger diameter than that of the
expected distended esophagus 15. Hence, as schematically shown in
FIG. 3, the sealing bladder 53 includes a residual volume 58 that
is able to engage with the ridges and pleated lining of the
esophagus without separating from contact with the pre-shaped,
undistended dimensions of the esophageal wall 16. As schematically
shown in FIG. 3, the residual diameter of the tampon bladder 53
further creates a number of reserve interpleatings 43 along its
surface in order to ensure that the pleated lumen of the esophagus
can be securely covered by the bladder hull over its entire
circumference without having to distend or stretch the bladder
material in order to effect an organ lumen obstruction. Due to the
prevention of any stretch of the bladder hull, the pressures inside
the bladder 53 needed to effect the desired sealing therefore can
be kept low, in the ideal case only slightly exceeding
intra-luminal organ pressure by a few millibars (cm H.sub.2O),
enabling a fluid seal at filling pressures that can be kept below
perfusion relevant trans-mural forces, and enabling the user to set
the barometrically measured pressure inside the bladder 53 equal to
such effected trans-mural forces.
Bladder Thickness
In order to meet the various design requirements on an atraumatic
sealing intra-esophageal bladder 53 in the best possible way, the
bladder 53 ideally is preferably made from microthin-walled, easily
pliable plastic film with a wall thickness of less than or equal to
about 0.03 mm. The seal bladder 53 is subjected to a fill pressure
of less than or equal to 30 mbar, being set ideally within a
pressure range of about 10 mbar to about 20 mbar, which are
pressures that are known to be non-critical for tissue perfusion,
and granting a sufficient degree of compatibility to the motility
of the esophagus 15. The bladder 53 can be made of blow-moulded,
foil-welded, or dipped material. The bladder 53 can be made from
polyurethanes, polyethylenes, silicone, natural and synthetic
rubbers, polyvinylchloride, or other materials offering adequate
pliability and stability in the required foil thickness range.
Bladder Length:
The membrane forming the esophageal bladder 53 is ideally sized to
cover the entire length of the esophagus. The bladder body
preferably is sized so that it can extend between the upper and the
lower esophageal sphincter. In most embodiments, the tampon-bladder
53 usually has a length of about 6 cm to about 15 cm, desirably
about 6 cm to about 9 cm.
Adjacent Organs
Further, the invention considers immediately adjoining structures
such as the great vessels, the accompanying nerves, the trachea and
main bronchi, the lungs 12 themselves and, not least, the heart,
particularly the left atrium. In contrast to conventional blocking
techniques, the invented reflux-sealing esophageal probe does not
endanger such structures due to perfusion or tissue critical
pressures effected by the permanent pressurized bladder seal
element 53.
Filling Media
Different fluids may be used as the medium for filling the
esophageal seal bladder 53, depending on the application. A
presently preferred bladder filling medium, which is distinguished
by compressibility as well as a certain adaptability of its own to
the fluctuations mentioned below is, for instance, a gaseous one.
Air is a presently preferred gas to provide the fluid medium for
filling the esophageal sealing bladder 53, and gas mixtures can be
used. However, a liquid medium for filling of the esophageal seal
bladder 53 is possible and viscous liquids, water, or gas/liquid
mixtures such as air and water, can be used.
Shift of the Bladder Filling Medium During Peristaltic, Lengthwise
Directed Contraction of the Esophagus (Swallowing):
Desirably, the invented probe 50 can be equipped with a special
mechanism, which permits an intra-bladder shift of the bladder
filling medium within the esophageal sealing bladder 53, giving the
device the required ability to remain stationary in the location
where it is placed and preventing a transport of the bladder
equipped probe 50 towards the stomach and/or preventing patient
irritating pressure peaks (bolus sensations) being generated in the
esophagus by the filling medium accumulating in the lower portion
of the seal bladder 53, below the peristaltic contraction wave. As
schematically shown in FIG. 3, within the segment of the probe 50
that carries the bladder 53, the device can include a second lumen
62 that is disposed next to the drainage or decompression lumen 61.
As schematically shown in FIG. 2, the drainage lumen 61 can be
arranged relative to the second lumen 62 in a manner such that a
channel 55 is formed between the interior 58 of the bladder 53 and
the second lumen 62. The second lumen 62 can be positioned relative
to the interior 58 of the bladder 53 by means of dividing fixtures
or baffle-like structures that bridge the passageway defining the
channel 55.
As schematically shown in FIG. 2, a conduit 52 that is disposed
around the feeding tube 54 can be configured to channel the air or
other gaseous medium filling the esophageal bladder 53 so as to be
redistributed with each wave of a peristaltic contraction from the
bladder portion 60 that is disposed below the peristaltic wave into
the bladder portion 59 that is disposed above and already released
from the peristaltic wave. In this way, an intra-bladder shift of
the filling medium is effected to accommodate the peristaltic wave
imposed on the esophagus. As shown in accompanying FIGS. 4-7 for
example, the described particular tube shaft profile within the
bladder carrying tube segment facilitates the volume shift that
prevents undesired pressure increases in the tamponade 53, pressure
increases that otherwise could pose a painful irritation of the
patient.
The inner cavity 58 of the tampon-bladder 53 may be filled with a
medium, through a delivery channel 55 lying between the delivery
lumen 62 and the inner cavity 58 of the tampon-bladder 53, from a
filling line 22 connected to the channel 55 via the delivery lumen
62. As schematically shown in FIG. 1, simply operated examples of
such a filling device are a reservoir or equalizing vessel 35,
particularly one situated outside the patient and connected via
filling line 22. A supply of the filling medium sufficient to fill
the inner cavity of the tampon-bladder 53, and in addition to allow
for the abovementioned functional fluctuations of the lumen and the
tonus of the esophageal wall 16 through further outflow or intake
of the medium by expansion and collapse of the tampon-bladder 53,
is kept in the reservoir or equalizing vessel 35.
In this connection it could be seen as an additional advantage for
the bladder filling medium to be actively led into the inner cavity
58 of the tampon-bladder 53 or withdrawn from the inner cavity
through the channel 55. Such active supply and withdrawal desirably
can take place through a pump 40 that is operated by the control
device and that is regulated preferably to compensate for any
extensive pressure-passive fluctuations in the tampon-bladder
53.
Stomach Probe, Volume Shift Mechanism, Advanced Profiles:
FIG. 2 illustrates the basic construction of an embodiment of an
anti-gastric reflux esophageal-stomach probe 50 according to the
present invention. A shaped, conduit body 52 is superimposed around
and over a delivery cannula 54 in the region of an inflatable
bladder 53. The conduit body 52 encloses a lumen 55 in its
interior. The lumen 55 also is shown in the view of FIG. 3, which
represents the cross section II-II through the stomach probe shown
in FIG. 2. In this example of the embodiment, the lumen 55 is
located between the delivery cannula 54 and the surface 56 of the
conduit body 52.
As can be seen in FIG. 2, several openings 57 defined through the
surface 56 of the shaped body 52 and desirably are distributed over
the entire surface 56 of the shaped body 52. The lumen 55 is
connected to the interior 58 of the inflatable bladder 53 via the
openings 57. This means that the openings 57 are configured and
disposed to permit volume or fluid exchange between the lumen 55
and the interior 58 of the inflatable bladder 53.
FIG. 4 shows an enlarged image of the disclosed shaped body 52 as
shown in the first embodiment of the invention shown in FIG. 2
wherein the shaped body 52 has an almost cylindrical external
shape. The number and shape of the openings 57 defined through the
surface 56 of the shaped body 52 may vary, depending on the end
use. In addition to the approximately round or oval openings 57
shown in FIGS. 2 and 4 for example, the openings 57 may also be
elongated, for example. The shape or contour of the openings 57 may
vary from being a largely round or oval cross-sectional profile, to
triangular, quadrangular or polygonal shaped openings 57. Nor must
the openings 57 be distributed more or less evenly over the surface
56 of the conduit body 52 as in the embodiment shown in FIGS. 2 and
4. Alternatively, the openings 57 may also be distributed unevenly.
In this case, it is important that the shape and arrangement of the
openings 57 permit adequate volume exchange between two sections,
59 and 60, of the inflatable bladder 53. The number of openings 57
may vary from one to any number of individual openings, e.g. 100 or
1000 openings. The number of openings 57 is restricted only by the
area of the surface 56 of the conduit body 52 and the shape of the
openings 57.
In one embodiment of the invention, the cross section of the shaped
body 52 may have several wall sections 64. As shown in FIG. 4 for
example, several wall sections 64 extend radially from the
cylindrical surface 56 of the shaped body 52 into the interior of
the shaped body 52. The free, front ends 65 of the wall sections 64
define a diameter, which corresponds approximately to the outer
diameter of the delivery cannula 54 and which are supported at the
delivery cannula 54 of the probe 50 and, together with it, define
at least one section 66 of the lumen 55. As shown in FIG. 3 for
example, when the shaped body 52 is located on the delivery cannula
54, the front ends 65 of the wall sections 64 rest on the delivery
cannula 54. The wall sections 64 may extend in a roughly
star-shaped configuration into the interior of the shaped body 52.
This arrangement guarantees an approximately even distribution of
the wall sections 64 and in turn guarantees secure support and
retention of the shaped body 52.
As shown in FIG. 3, together with the delivery cannula 54, the
lumen 55 inside the shaped body 52 can be divided into separate
lumen sections 66. A single lumen section 66 is delimited by two
wall sections 64, the portion of the surface of the shaped body 56
which lies between the two wall sections 13 and the portion of the
surface of the delivery cannula 54 which is located between the
contact surfaces of the front ends 65 of the wall sections 64. In
this example of the embodiment shown in FIGS. 2, 3 and 4, the
shaped body 52 has eight wall sections 64, which all extend in a
finger-like manner by roughly the same amount into the shaped body
52. These wall sections 64 can form a passageway with their front
ends 65, whose dimensions correspond approximately to those of the
delivery cannula 54. The shaped body 52 can therefore be mounted
easily onto the delivery cannula 54.
In other embodiments of the invention, the number of wall sections
64, however, may vary arbitrarily, and thus influence the shape of
the lumen 55 or the individual lumen sections 66. The depth to
which the wall sections 64 penetrate into the interior of the
shaped body 52 also may vary, and this depth determines the
position of the shaped body 52 in relation to the delivery cannula
54. Depending on the particular application, the longitudinal axis
36 of the shaped body 52 may also be displaced in relation to the
longitudinal axis 37 of the delivery cannula 54. This means that
the shaped body 52 need not necessarily sit more or less
concentrically on the delivery cannula 54 as in the embodiment
shown in FIGS. 2, 3 and 4 where the longitudinal axis 36 of the
shaped body 52 coincides with the longitudinal axis 37 of the
delivery cannula 54.
In the region of the axial front side of the shaped body 52, the
lumen 55 may expediently be connected to a delivery channel 62, via
which the inflatable bladder 53 can be filled with a fluid. In this
embodiment shown in FIGS. 2 and 3, the delivery channel 62 for the
filling fluid extends, at least in parts, into the conduit body 52
and has at least one access opening 51, which connects the delivery
channel 62 to the lumen 55 and joins the lumen 55 with the interior
58 of the inflatable bladder 53. The access opening 51 guarantees
good volume equalization between the sections of the inflatable
bladder 53, and can also be produced using simple techniques. The
access opening 51 may extend over roughly the entire length of the
shaped body 52. As schematically shown in FIGS. 2 and 3 for
example, the shaped body 52 may have at least one access opening 51
which extends in roughly the longitudinal direction of the shaped
body 52 over at least 50 to 60%, preferably over up to 70%, and
especially over up to 80%, of the total length of the shaped body.
This arrangement can be produced using simple techniques and
simplifies the construction of the stomach probe 50, since the
inflatable bladder 53 can be filled directly via the lumen 55 with
which it is connected.
In embodiment shown in FIGS. 2 and 3, the access opening 51 runs
radially in relation to the shaped body 52. The access opening 51
of the delivery channel 62 need not necessarily run radially, but
may also run in the region around the axial front surface of the
shaped body 52 rather than axially to the shaped body 52. In other
embodiments of the disclosed stomach probe 50, the delivery channel
62 also may run along the outside of the delivery cannula 54. As
shown in FIG. 5, the delivery channel 62 may, for example, be
located, at least partly, in an indentation 63, which runs along
the delivery cannula 54.
FIGS. 6 through 10 show perspective views of further embodiments of
the disclosed shaped body 52. FIGS. 6 and 7 show second and third
embodiments of the disclosed shaped body 52. The reference numbers
used in FIGS. 2 through 5 refer to the same components as those in
FIGS. 6 and 7.
As shown in FIGS. 6 and 7, each shaped body 52 can have a central,
roughly tubular structure 68, with a roughly circular transverse
cross section. The inner diameter of the shaped body 52, as well as
the contact surface between the shaped body 52 and the delivery
cannula 54, are formed by the tubular structure 68. As shown in
FIG. 7, the shape of the inner cover surface 69 roughly corresponds
to the shape of the surface of the delivery cannula 54. As shown in
FIGS. 6 and 7, several wall sections 70 extend radially outwards
from the central, tubular structure 68. At the outermost end 71 of
each wall section 70 lying opposite to the central, tubular
structure 68 is a surface 72, which runs roughly transversely to
the wall section 70.
In the embodiment of FIG. 6, the shaped body 52 has four wall
sections 70 arranged roughly in a circle. The wall sections 70,
together with the associated surfaces 72, form an approximately
T-shaped profile in the cross section. This T-shaped profile can be
produced easily, and provides a lumen 55 of sufficient size, as
well as a good contact surface for the inflatable bladder 53. In
the embodiment of FIG. 7, the shaped body 52 has five wall sections
70 arranged in an approximate star-shaped configuration around the
tubular structure 68. In the embodiment of FIG. 7, the wall
sections 70, together with their respective transverse surfaces 72,
form a roughly L-shaped profile in cross section. This L-shaped
profile can also be produced using simple techniques, and provides
for a lumen and contact surface that permits rapid volume exchange
between the sections of the inflatable bladder 53.
The T- and L-shaped profiles of the shaped bodies 52 shown in FIGS.
6 and 7 are located at such a distance from each other, or are
dimensioned in such a way, that the transverse surfaces 72 of two
adjacent T- or L-shaped profiles are at a distance from each other.
This means that every two of the transverse surfaces 72, which
define the surface 56 of the shaped body 52, define an opening 73
or slit, which runs along the length of the shaped body 52. In
these examples of the embodiment shown in FIGS. 6 and 7, the lumen
55, which is located here between the transverse surfaces 72 and
the tubular structure 68, is divided by the T-shaped profiles or
L-shaped profiles into separate lumen sections 66. The shape of an
individual lumen section 66 is thereby determined by in each case
two adjacent T-shaped profiles or L-shaped profiles and the portion
of the surface 56 of the tubular structure 68 enclosed by them. The
number of wall sections 70 may be varied, depending on the end use.
If this end use changes, the shape and the number of lumen sections
66 and openings 73 in the surface 56 of the shaped body 52 also
desirably change.
In a further embodiment of the invention, the wall sections 70 may
also be arranged unevenly around the tubular structure 68, unlike
the examples shown here. The transverse surfaces 72 at the ends 71
of the wall sections 70 also can be dispensed with in some
embodiments. In this case, the surface 56 of the shaped body 52 is
determined by the ends 71 of the wall sections 70. The number of
wall sections 70 may be increased accordingly, and there may be
between about 5 and about 15 wall sections 70, for example.
The abovementioned first through fourth embodiments of the
disclosed shaped body 52 in FIGS. 2-7 also can be twisted, rather
like a screw, and thus can be shaped like a coil.
FIG. 8 shows a further embodiment of the disclosed shaped body 52
in the form of a spiral that is formed as a coil 74. The inner
diameter of the coil 74 corresponds approximately to the outer
diameter of the delivery cannula 54. In this embodiment, the lumen
55 also has a spiral shape. In use, that is when the shaped body 52
is located on the delivery cannula 54, as shown in FIG. 8, the coil
74 is defined by a plurality of consecutive windings 77. Each
winding 77 of the coil 74 helically wraps once completely around
the delivery cannula 54. As shown in FIG. 8, an opening 33, which
runs spirally around the delivery cannula 54, is defined between
the individual windings 77 of the coil 74 and encloses the lumen
55. The thickness of the coil 74 determines the height of the lumen
55. The coil 74 may have a roughly circular cross section. However,
alternatively, the cross section of the coil 74 may have an oval
shape or angular shape.
With the coil 74 of the shaped body 52 shown in FIG. 8, the inner
diameter of the shaped body 52 is determined by the inner diameter
of the coil 74. The contact surface between the shaped body 52 and
the delivery cannula 54 corresponds, in this case, to the spiral
installation line or surface of the individual windings 77 of the
coil 74. Whether it is in the form of a line or a planar
configuration will be determined by the cross section of the coil
74.
In addition to single or interconnected coils, a pipe-like or
tubular structure also can be applied. As shown in FIG. 8 by a line
consisting of a sequence of dots and dashes, pipe-like or tubular
structure can have openings. The external shape of this type of
shaped body 52 would then be similar to the shaped body shown in
FIG. 2.
In a further embodiment, the lumen 55 may also be defined by
several coils, for example two coils, which are roughly
concentrically disposed so that the one is on top of, i.e.,
surrounding, the other. In this case, the two coils may have the
same gradient or different gradients. The coils also can be
superimposed so that each one runs in opposite direction to the
other one. In this case, the lumen 55 is defined by the
intermediate space between the individual windings of the relevant
coil, i.e., by the overlapped sections of these intermediate
spaces.
FIG. 9 shows another embodiment of the disclosed shaped body 52
that is pipe-like or tubular in shape and has a net-like
construction 25. The inner diameter of the shaped body 52
corresponds approximately to the outer diameter of the delivery
cannula 54. As shown in FIG. 9, the net-like construction 75, the
inner diameter of the shaped body 52 and the contact surface
between the shaped body 52 and the delivery cannula 54 are
determined by the individual connecting pieces 78 of the net-like
construction 75. In this embodiment shown in FIG. 9, the lumen 55
is located within the mesh or openings 76 of the net-like
construction 75, which are at least partly connected to each other,
and thus permit volume exchange between the individual openings 76
of the net-like construction 75.
In a further embodiment of the invention, the shaped body 52 may
also comprise several layers of the net-like construction 75, as
FIG. 10 shows. These layers of the net-like construction 75 are
arranged roughly concentrically in relation to each other, whereby
the inner diameter of the innermost layer corresponds approximately
to the outer diameter of the delivery cannula 54. In this
embodiment, the lumen 55 is defined by the holes 76 in the net-like
construction 75, which overlap at least in parts. This means that
the overlapping holes 76 of the individual layers of the net-like
construction 75 form channels or individual lumen sections 66. When
the shaped body 52 is in the state it is in during use, i.e., when
the shaped body 52 is located on the delivery cannula 54, at least
part of the lumen section 66 extends at least in sections along the
delivery cannula 54, and thus permits volume exchange between the
individual sections of the inflatable bladder 53. This net-like
construction can be produced efficiently and can be premounted onto
the coil, and so can simplify assembly.
The dimensions of the different embodiments of the shaped body 52
described here may vary, depending on the end use. In practice,
however, an approximate length of about 6 cm to about 12 cm, and
especially a length of about 6 cm to about 9 cm, has proved to be
particularly advantageous for the shaped body 52. They provide a
sufficiently large contact surface for the inflatable bladder 53.
At the same time, an adequate volume exchange between all the
sections of the inflatable bladder 53 is guaranteed. The outer
diameter of the shaped body 52 also depends on the end use, as well
as on the dimensions of the delivery cannula 54 and the inflatable
bladder 53, and is advantageously in the region of between about 7
mm and about 12 mm, and especially between about 6 mm and about 8
mm. These dimensions guarantee good volume exchange between the
sections of the inflatable bladder 53. However, for special end
uses, the dimensions of the shaped body 52 may deviate from the
abovementioned dimensions.
The inflatable bladder 53 is filled with a fluid, e.g., water, via
the delivery channel 62, whereby the fluid flows through the access
opening 51 of the delivery channel 62 into the lumen 55 of the
shaped body 52. The fluid flows into the interior 58 of the
inflatable bladder 53 through the openings 57, 73, 76 and 33 of the
shaped body 52. As the inflatable bladder 53 fills with the fluid,
the inflatable bladder 53 expands until at least a portion of its
exterior surface lies almost completely against an uninterrupted
annular portion of the wall 16 of the esophagus 15, as can be seen
in FIG. 3. This enables the esophagus to largely be sealed off from
liquids or solid substances, which tend to move up from the region
of the stomach 18 towards the pharyngeal cavity, and thus to keep
the windpipe free from harmful substances.
The swallowing motions made by the patient who has been fitted with
the disclosed stomach probe 50 cause the muscles to contract along
the wall 16 of the esophagus 15. These muscles create one or
usually several annular constrictions in the esophagus 15, which
are propagated along the esophagus 15 from the larynx region
towards the stomach 18.
In order to illustrate the functions of the shaped body 52, the
movement of a single, annular constriction will now be examined. In
the area around the inflatable bladder 53, the annular constriction
in the esophagus causes a partial reduction in the outer diameter
of the inflatable bladder 53, i.e., a local narrowing 31 of the
inflatable bladder 53 occurs, which is shown in FIG. 2 as a dashed
line. This narrowing 31 divides the inflatable bladder 53 into two
sections, 59 and 60. While the esophageal constriction is imposed
as a wave that moves along the inflatable bladder 53 as when
swallowing occurs, the dimensions of the individual sections, 59
and 60, change. In this case employing the probe 50 of the present
invention, however, the volume of fluid that can be contained in
the relevant sections, 59 and 60, of the inflatable bladder 53,
also changes. The disclosed shaped body 52 provides a lumen 55,
which permits rapid volume exchange between the individual
sections, 59 and 60, of the inflatable bladder 53. The surface 56
of the disclosed shaped body 52 provides, if necessary, a
relatively rigid contact surface for the constricted wall section
31 of the inflatable bladder 53. The lumen 55 is therefore kept
free of these external influences, and is available entirely for
volume exchange. As schematically shown in FIG. 2, while the
constriction 31 moves along the inflatable bladder 53 in the
direction of arrow 30, the fluid is forced out of the interior 58
of the second section 60 of the inflatable bladder 53 via the
openings 57 beneath the second section 60 of the inflatable bladder
53, and the fluid is forced into the interior 58 of the first
section 59 of the inflatable bladder 53 via the openings 57 beneath
the first section 59 of the inflatable bladder 53.
A stomach probe of the type disclosed in German Utility Model
Application No. 202006002832.3 has been improved in the present
disclosure. In accordance with the present invention, the lumen 55,
which is located between the delivery cannula 54 and the inflatable
esophageal seal 53 and which is connected to the interior 58 of the
inflatable esophageal seal 53, can be produced by a relatively
simple technique, and at the same time guarantees adequate volume
equalization between the partial volumes of the inflatable
esophageal seal 53.
The separate shaped body 52 of the stomach probe 50 can be produced
by a simple technique, since it can be prefabricated as a separate
component. The shaped body 52 described above is preferably made
from plastic and is produced desirably by an extrusion process.
This manufacturing process enables the shaped body 52 to be
produced by a relatively simple and quick technique. Alternatively,
the shaped body 52 may be produced by casting or injection
molding.
In principle, the materials used for the shaped body 52 are ones
that can deform easily to suit the human body, i.e., they do not
injure the patient whilst being inserted or during long-term use of
the probe, but they are rigid enough to provide a non-collapsible
shape when peristalsis occurs over the shaped body 52. Advantageous
materials are, for example, PVC, PUR, blends of PVC and PUR, blends
of PUR and polyamides, and/or silicones. These materials guarantee
good compatibility with the tissue of the patient. These materials
can be shaped easily and thus reduce the risk of injury during
introduction of the stomach probe 50 into the patient, yet these
materials are stable enough to maintain the lumen 55 during
peristalsis.
During assembly of the stomach probe 50, the separate shaped body
52 desirably can be mounted as a finished component on the delivery
cannula 54, and attached to the delivery cannula 54. Applying the
shaped body 52 to the delivery cannula 54 determines the shape of
the lumen 55 at the same time, which ensures that there is
sufficiently rapid volume exchange between the sections of the
inflatable esophageal seal 53. This configuration simplifies
assembly of the stomach probe 50, since the number of individual
processing stages needed to produce the lumen 55 can be reduced.
Such simplified assembly results in a potential for reducing both
time and costs when producing the stomach probe 50.
The shaped body 52 may have a tubular structure, whose internal
shape corresponds roughly to the external shape of the delivery
cannula 54. The tubular structure enables the shaped body 52 to be
attached roughly concentrically to the delivery cannula 54. These
complementary shapes simplify the assembly process for the
disclosed stomach probe 50, as the shaped body 52 desirably can be
applied to the delivery cannula 54 by means of a sliding process.
Since the inner diameter of the relevant shaped body 52 corresponds
approximately to the outer diameter of the delivery cannula 54, or
is at least slightly smaller than the outer diameter of the
delivery cannula 54, a slight press-fitting effect occurs during
mounting of the shaped body 52 onto the delivery cannula 54. The
resulting static friction fixes the shaped body 52 radially and
axially onto the delivery cannula 54 and guarantees axial and/or
radial fixing of the shaped body 52 on the delivery cannula 54 of
the stomach probe 50.
Alternatively, the shaped body 52 may also be fixed onto the
delivery cannula 54 by means of adhesion, e.g., by applying an
adhesive at least on part of the contact surface between the shaped
body 52 and the delivery cannula 54. Alternatively, the shaped body
52 may also be fixed by material-bonding whereby, for example, at
least part of the contact surface between the shaped body 52 and
the delivery cannula 54 is treated with a solvent. Solvent etching
of the shaped body 52, and/or the delivery cannula 54, at least in
part, guarantees good bonding of the two components. In principle,
any possible combination of the above-mentioned fixing techniques
are feasible as a means of attaching the shaped body 52 onto the
delivery cannula 54.
The final, assembled stomach probe 50 desirably can be used for
treating comatose patients, for example, who are unable to feed
themselves. In this application, the disclosed stomach probe 50,
i.e., the delivery cannula 54 of the stomach probe 50, is inserted
into the patient's esophagus, whereby the section of the stomach
probe 50 that is fitted with the inflatable bladder 53 is located
above the entrance to the stomach 18 in the esophagus 15. The
presently preferred length of the shaped body 52 of approximately
about 6 cm to about 9 cm ensures that the shaped body 52 fits well
in the section between the upper and lower sphincter of the
esophagus.
To improve orientation, the stomach probe 50 may be fitted with at
least one radiopaque marker, such as a metal ring 67. The
radiopaque marker 67 makes it possible to check that the probe 50
is in the correct position by means of an X-ray image. The marker
67 facilitates positioning of the probe 50 in the patient and acts
as a reference point to orientating organs, such as the diaphragm
and/or thyroid, on the X-ray image of the thorax. As shown in FIG.
2, more than one marker 67 may be employed. These radiopaque
markers 67 may be placed at the shaped body 52, the delivery
cannula 54 and/or the inflatable bladder 53.
* * * * *